Yawning

My snake seems to be yawning quite often...
Every night at about this time he will peek his head out of either hide, and just sit there until I decide to go to bed, and probably after that too.
Every once and a while I will catch him yawning when hes sitting like this.
He isn't mouth breathing, and I don't think he is resetting his jaw since he has done it every night since he ate 4 days ago. Do snakes really yawn that much? He has no mucus that I can see...I suppose tomorrow I can look inside of his mouth if I can figure out how to open it..

Yes, all three of mine do it. I'll get mine out sometimes, and they will cruise around my fingers. When they settle down on my stomach, I can get a good yawn out of them. I think they just do it to get a deeper breath every so often. Just like us. lol. I wouldn't worry too much about it. :)